Solar LBIC scanning of high‐efficiency point‐contact silicon solar cells

Abstract

The induced current response from a High Efficiency Concentrator (HECO) monocrystaline Si solar cell was mapped as a function of surface position and cell bias by using a solar light beam induced current (S‐LBIC) mapping system while at the same time dynamically biasing the whole cell with an external voltage [1,2] Recombination accounts for a major portion of the reduction in quantum efficiency in these cells [3,4]. This paper examines the spatial distribution of defect mechanisms causing a reduction of collected photocurrent of the backside point‐contact device structure [5] while under spot illumination. By examining the bias dependence of the S‐LBIC maps, the identification of current loss mechanisms of solar cells under concentrated solar irradiance may be improved. The techniques employed to interpret the spatially distributed I‐V curves are discussed and results presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)